Sunaryo Hardjowijoto

Prostate-specific antigen and prostate-specific antigen density cutoff points among Indonesian population suspected for prostate cancer

Purpose: Racial differences exist in the incidence of prostate cancer (PCa). Although many studies have looked at the performance of prostate-specific antigen (PSA) and PSA density (PSAD) in the detection of PCa, only a few have looked at it in relation to Indonesian men. The objective of this study is to find out better PSA and PSAD cutoff point in the detection of PCa in Indonesian men. Methods: A total of 404 consecutive Indonesian men underwent prostate biopsy for suspicion of PCa from 2008 to 2011. The biopsy criteria include one or more of the following: serum PSA more than 10 ng/mL, PSAD more than 0.15 if PSA 4–10 ng/mL, hypoechoic lesion during transrectal sonography and/or abnormal digital rectal examination. Results: Forty five out of 404 (11.1%) had positive biopsies. The mean age, prostate volume, PSA and PSAD were respectively 64.06 years, 43.03 mL, 45.59 ng/mL and 1.15. Of the 404, 131 cases (32.4%) were confirmed to be urinary retention. Positive urine culture found in 182 cases (45%). The cutoff point to detect PCa as estimated by the receiver operating characteristics was 6.95 ng/mL for PSA (sensitivity 97.8%, specificity 19.6%) and 0.7072 for PSAD (sensitivity 62.2%, specificity 78.7%). Positive predictive value for this PSA and PSAD cutoff point were 11.6% and 27.5% respectively (P=0.004 and P=0.000). There was a significant correlation between hypoechoic lesion and positive biopsy results (P =0.000). Urinary retention elevates PSA cutoff point to 14.55 (sensitivity 90.9%, specificity 50%), while positive urine culture alters almost no PSA cutoff elevation. Conclusions: PSA and PSAD cutoff point for Indonesian men in this series is relatively different from international consensus. Furthermore, these data show that PSA and PSAD cutoff point must be adjusted to racial variation to discriminate between malignant and benign disease. Urinary retention is a significant factor for PSA cutoff increase.